The Study On 'Constant Tendency' And 'Double Checks' Of Malthus

On the Principle of Population (aggregately seven editions) expressed Malithus's idea on the population. And the main points of his idea on population are 'constant tendency' which evolved from 'two axiom' and 'tow progression' and 'double checks' the method of population control.Malthuism principle of population was introduced into China early, and made broad influence. The prevenient study on the principle of population didn't pay attention to the difference between the first edition and the second edition, especially misconstrue 'constant tendency' and 'double checks', and didn't pay attention to the relation between Malthus's idea on population and his idea on economics.This study want to start from the all life of Malthus the backdrop and sources of his idea on population, compare 'constant tendency' and 'double checks' in the first and the second edition, discuss the principle of population of Malthus.And the conclusion is Malthus's idea on population was completed in the second edition. So we should study his idea by his two editions not only one of them; his 'constant tendency' is the comparing of two latent tendency, Malthus himself think that 'preventive check' is more better than 'positive check'.